Selective muting for conference call participants

ABSTRACT

The present invention is directed toward conference calls and methods, devices, and systems for facilitating a conference call. Specifically, the present invention allows participants of a conference call to selectively alter or mute other participants&#39; voices in a conference call. More specifically, a number of participants may be associated with a single communication device and only a subset of those participants may have their voice signal altered or muted during the conference call.

FIELD

The invention relates generally to communication systems and conferencecalls between multiple participants, where more than one participant isusing a single communication endpoint.

BACKGROUND

Conference and multi-person calling have become increasingly popular andcommon calling techniques for businesses as well as individualsubscribers. These multi-line calling techniques allow multiple callersto be connected thereby allowing the callers to communicate with eachother. The user may couple two or more telephone lines such that theuser and the parties associated with the respective telephone lines maycommunicate with each other in a conference call. Alternatively, theuser may place multiple calls and communicate with each of the calledparties without allowing the called parties to communicate with eachother.

Many conferencing systems employ a dedicated line for each participantin the conference call. The reason typical conferencing systems requireparticipants to use their own communication device is because signalprocessing is thus made a much easier task and additional features canbe provided to the customer. For example, if a single participant isusing a dedicated communication device and subsequently is communicatingwith the other participants via a dedicated line, that singleparticipant's voice can be easily separated from the other participants'voices and can be altered in a relatively easy fashion. In other words,when each participant is using a dedicated hard line, there exist manymethods that allow one participant to alter another participant's voice.Participants can cut out audio or otherwise alter another participant'sparticipation if they do not wish to speak with him/her. Participantsmay also mute their own dedicated communication device if they wish totalk to someone else and have a side conversation without transmittingtheir audio to everyone.

One drawback to such a configuration is that each participant is limitedto using their own communication device when conferencing with the otherparticipants. When many participants from the same office are on thesame conference, it can be a nuisance to require each participant tohave their own communication device. It is often desirable for theparticipants who work in the same office to all gather in a common area,i.e., a conference/meeting room, to participate in the conference calltogether. Having several participants in the same room may help toimprove the conference experience because these participants canactually see and interact with one another in a natural setting.Unfortunately, when several participants are in the same room there maynot be enough communication devices for each participant to controltheir own audio. One conference room may be equipped with threecommunication devices, and this will suffice as long as no more thanthree participants wish to engage in the conference call in the sameroom. As long as each participant is able to have their owncommunication device, known methods can be employed to enhance theconference experience for each participant.

However, if there are four participants that wish to take part in theconference in the same room and there are only three communicationdevices, the participants quickly become frustrated. At least two of theparticipants will need to share a single communication device or anothercommunication device will need to be tracked down and brought into theconference room. If two of the participants attempt to share the samecommunication device, it becomes very difficult for other participantsto mute and/or alter the voice signal from one of the two participants.Other participants may wish to only listen to what the first sharingparticipant has to say and may wish to mute the second sharingparticipant. To do this, the listening participant must toggle betweenmuting and not muting of the shared communication device as the sharingparticipants take turns speaking.

Another problem that arises when participants attempt to share acommunication device during a conference is that if one participantwishes to have a side conversation with another participant then theshared communication device needs to be muted. This may be acceptable inthe event that only two participants are sharing a communication device,but if ten people are sharing the communication device, then all tenpeople must be muted if two of the participants wish to have a sideconversation. The advantage of having multiple participants share acommunication device is that there is no need to supply quantities oftelephone equipment in proportion to the number of attendees. If moreparticipants wish to engage in the conversation, no additionalcommunication devices need to be employed. However, as participantsbegin to share a communication device, the advantages offered by using asingle communication device, i.e., processing capabilities andadditional features, become more difficult to implement.

Therefore, it would be desirable to have a communication device thatprovides the scalability of a shared communication device while alsoproviding enhanced communication features offered by multiple dedicatedcommunication devices.

SUMMARY

Embodiments of the present invention are directed generally to device,system, and method for allowing participants in a conference call toselectively mute themselves and/or other conference call participants.Specifically, a number of participants may be associated with the samecommunication device and only a subset of those participants may bemuted or have their voice signals altered in some other fashion

In one embodiment, the present invention is directed to a method offacilitating a conference call. The method includes the steps of:

receiving a sound signal at a microphone;

determining a relative spatial location of a source of the receivedsound signal;

based on the determined location of the source of the received soundsignal, processing the received sound signal by performing at least oneof the following steps:

-   -   (i) selectively altering the received sound signal in a first        manner in the event that the received sound signal is received        from a first determined location; and    -   (ii) selectively altering the received sound signal in a second        manner in the event that the received sound signal is received        from a second determined location, wherein the first and second        manners are different.

A spatial location of a source of the received sound signal is typicallydetermined by implementing a microphone array that is operable toreceive the same spoken signal at different times. For audiolocalization in three dimensions of space, the microphone array shouldcomprise three sets of microphones (i.e., four microphones). Relativephase information is used to recognize the source position for speechsignals. The delay between signals received at each microphone pair canbe determined using an inter-correlation function between signal energy.The maximum of the inter-correlation function provides a time differenceof arrival for each microphone pair. Then one of a number of methods maybe employed to estimate the position of an acoustic source. One suchmethod utilizes an analytic approach. Given the relative position ofmicrophones in the microphone array, each possible time delaycorresponds to a sphere of positions whose distance corresponds to thedistance that sound travels during the delay. The time difference ofarrivals of two microphones corresponds to a hyperbolic function that isthe intersection of two spheres. Given three microphone pairs, one cancompute the intersection of these hyperbolic functions to substantiallypredict the position of the acoustic source.

As used herein a “spatial origin” or “spatial location” may be definedas a physical location, either in space, or compared to a particularreference point and/or as a corresponding measured parameter (e.g.,phase difference, time difference of arrival, amplitude difference,spectral characteristic differences, etc.) that can be correlated to aphysical location. The spatial locations of the source of a signal maybe represented in Cartesian coordinates, polar coordinates, or any otherlocation scheme known in the art. Furthermore, a spatial location doesnot necessarily need to describe a single point in space. Rather, aspatial origin may correspond to a range of spatial positions.

Likewise a “set of spatial locations” corresponds to a collection of oneor more spatial locations. A set of spatial locations may define asingle point in space, a line, an area, and/or a volume of space.Specifically, a set of spatial locations can define a position orpositions in one, two, or three dimensions having determined axialextents. Moreover, a set of spatial locations may correspond to a rangeof time/phase/amplitude differences associated with a range of spatiallocations

In accordance with at least some embodiments of the present invention, asignal received from a first participant may be separated from a signalreceived from a second participant that is using the same communicationdevice as the first participant. The signal received from the firstparticipant may be selectively altered independently of a signalreceived from the second participant. In other words, the signal fromthe first participant may be muted, if such an action is desired,whereas a signal received from the second participant may not beadjusted at all. Furthermore, even if the signals from the first andsecond participant are received at substantially the same time at themicrophone array, each signal may be separated and independentlyprocessed.

This affords multiple participants to share a single communicationdevice during a conference call. Furthermore, more participants can bedynamically added to the conference call without requiring additionalcommunication devices to support the new participants. Additionally,processing capabilities are not sacrificed when a communication deviceis shared, unlike when a communication device was shared in the priorart.

These and other advantages will be apparent from the disclosure of theinvention(s) contained herein. The above-described embodiments andconfigurations are neither complete nor exhaustive. As will beappreciated, other embodiments of the invention are possible utilizing,alone or in combination, one or more of the features set forth above ordescribed in detail below.

As used herein, “at least one”, “one or more”, and “and/or” areopen-ended expressions that are both conjunctive and disjunctive inoperation. For example, each of the expressions “at least one of A, Band C”, “at least one of A, B, or C”, “one or more of A, B, and C”, “oneor more of A, B, or C” and “A, B, and/or C” means A alone, B alone, Calone, A and B together, A and C together, B and C together, or A, B andC together.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts a communication system for facilitating a conference inaccordance with at least some embodiments of the present invention;

FIG. 2 depicts an enhanced communication device in accordance with atleast some embodiments of the present invention;

FIG. 3A depicts a one-dimensional microphone array for use in anexemplary communication device in accordance with at least someembodiments of the present invention;

FIG. 3B depicts a two-dimensional microphone array for use in anexemplary communication device in accordance with at least someembodiments of the present invention;

FIG. 3C depicts a three-dimensional microphone array for use in anexemplary communication device in accordance with at least someembodiments of the present invention;

FIG. 4 depicts a spatial representation of participants in accordancewith at least some embodiments of the present invention;

FIG. 5 is a block diagram depicting a data structure employed inaccordance with at least some embodiments of the present invention;

FIG. 6 is a flow chart depicting a method for initializing a conferencecall in accordance with at least some embodiments of the presentinvention; and

FIG. 7 is a flow chart depicting a method for facilitating a conferencecall in accordance with at least some embodiments of the presentinvention.

DETAILED DESCRIPTION

The invention will be illustrated below in conjunction with an exemplarycommunication system. Although well suited for use with, e.g., a systemhaving a conference bridge or other similar conferencing hardware, theinvention is not limited for use with any particular type ofcommunication system or configuration of system elements. Those skilledin the art will recognize that the disclosed techniques may be used inany communication application in which it is desirable to share acommunication device during a conference call.

As used herein a “conference call” is a communication between three ormore individuals, at least two of whom are sharing a communicationdevice to communicate with at least one other participant.

Referring initially to FIG. 1, an exemplary communication system 100will be described in accordance with embodiments of the presentinvention. The communication system 100 generally comprises acommunications network 104 (e.g., a packet switched network and/or acircuit switched network), a plurality of telecommunication devices 108,a conference bridge 112, and an enhanced communication device 116.

The communications network 104 can be any data and/or distributedprocessing network, such as a PSTN, the Internet, or an enterprisenetwork. The network 104 typically includes proxies, registrars, androuters for managing packet flows in the case of a packet-switchednetwork.

The communication devices 108 and/or 116 may be packet-switched and caninclude, for example, IP hardphones such as Avaya Inc.'s 4600 Series IPPhones™, IP softphones such as Avaya Inc.'s IP Softphone™, PersonalDigital Assistants or PDAs, Personal Computers or PCs, laptops,packet-based H.320 video phones and conferencing units, packet-basedvoice messaging and Interactive Voice Response (IVRs), and packet-basedtraditional computer telephony adjuncts.

The communication devices 108 and/or 116 may also be circuit-switched inthe event that a circuit-switched network is utilized. Circuit-switchedcommunication devices 108 can include, for example, wired and wirelesstelephones, PDAs, H.320 videophones and conferencing units, voicemessaging and response units, and traditional computer telephonyadjuncts.

The conference bridge 112 comprises a processor 120 and a mixer 124. Theprocessor 120 is operable to perform various signal processing functionson any incoming signal. For example, if a first participant wishes tomute a second participant during a conference, then the firstparticipant may send a command to the processor 120 requesting suchservice. The processor 120 will then mute or otherwise remove the secondparticipant's voice signal before it is transmitted to the firstparticipant. The processor 120 may also be able to adjust eachparticipant's voice signal such that a normalized signal is transmittedto every other participant. In other words, the processor 120 maydecrease the volume of participants who are speaking loudly and mayincrease the volume of participants who are speaking quietly such thatthe volume of every participant's voice signal is approximately thesame. Similarly, the processor 120 may compensate for a communicationsystem that attenuates or amplifies a participants voice by processingeach participant's voice individually. The processor 120 is alsooperable to perform any other predetermined functions within a memory ofthe conference bridge 112.

Users of the external and internal endpoints may wish to communicatewith one another across the communication network 104. In the event thata simple point-to-point connection is desired, the two subject endpointsare directly connected by hardware within the communications network 104and a single communication path is established. However, when severalusers of the external endpoints wish to conference with each othersimultaneously, the conference bridge 112 is typically employed. Theconference bridge 112 connects each channel from each endpointparticipating in the conference call such that every participant of theconference call can hear what any one of the other participants issaying at a given time. This is accomplished by a number of mechanisms.One such mechanism is the received signals from every endpoint aresummed together by the mixer 124 into a single outgoing signal for eachparticipant. Each participant's received signal is generally not addedto (or subtracted from) the summed signal from the summed signal that agiven participant will receive. Specifically, if three parties A, B, andC are joined in a conference call, the signals from parties A and B aresummed and sent to party C, the signals from parties A and C are summedand sent to party B, and the signals from parties B and C are summed andsent to party A. This is typically accomplished by having each channelof the conference bridge 112 have its own mixer 124.

Traditional mixing of user inputs may be utilized as noted above or moresophisticated methods of mixing, for example “edgepoint” mixing may beemployed. A description of edge point mixing can be found in PCT PatentApplication No. 00/72,560 to Truechat, Inc., the contents of which areherein incorporated by this reference. In the '560 application, eachcommunication device is equipped with a mixer that allows for mixing ofother participant's voice signals at the communication device (edge),rather than at a central conference bridge.

It should be emphasized that the configuration of the conference bridge,communication device, and other elements as shown in FIG. 1 is forpurposes of illustration only and should not be construed as limitingthe invention to any particular arrangement of elements. For example,the conference bridge 112 logic may be included in a switch/server or beconfigured as an adjunct to a switch/server.

Referring now to FIG. 2 an enhanced communication device 116 will bedescribed in accordance with at least some embodiments of the presentinvention. The enhanced communication device 116 comprises a microphonearray 204, a participant locator 208, a signal separator 212, aprocessor 216, a memory 220, a user interface 224, and a transceiver228. The enhanced communication device 116 is generally configured andmeant for use by more than one participant at a time. Of course a singleparticipant may utilize the enhanced communication device 116, butcertain inventive aspects may not be completely realized.

The microphone array 204 is typically a set of two or more microphones.As can be appreciated, however, other types of voice-to-electronicsignal transducers may be utilized. The microphones in the microphonearray 204 are generally spaced apart such that a single voice signal isreceived by one microphone at a different time than the signal isreceived at a second microphone. The result is a phase differencebetween the signal received by the first microphone and the signalreceived by the second microphone. The phase difference in receivedsignals may be used to determine where a participant is in relation tothe microphone array 204. In other words, the phase difference may beable to help identify the location where a particular voice signaloriginated.

The'microphone array 204 may also comprise one or more speakers that areable to transform received electrical voice signals from the transceiver228 into sound signals that can be heard or otherwise perceived by theparticipant(s) using the enhanced communication device 116.

The participant locator 208 is operable not only to measure the phasedifference between the signal received at the first microphone and thesignal received at the second microphone, but also to correlate thephase difference to a location of a particular participant. Theparticipant locator essentially can spatially identify a participant ofa conference call by simply measuring the phase difference of a signalreceived by the microphone array 204.

The signal separator 212 is operable to take the identification from theparticipant locator 208 and assign the voice signal to a virtualchannel. A virtual channel is embodied not as a physically separatechannel dedicated to a particular participant. Rather, a virtual channelis the association of a set of measured parameters to a participant. Theset of measured parameters may include phase shift as noted above and/oran amplitude difference of a received signal as measured by themicrophone array 204. Additionally, the set of measured parameters mayfurther include measuring spectral characteristics (i.e., frequency,pitch, tone, etc.) to identify participants as they move about themicrophone array 204. The association for a received signal ismaintained such that the received signal may be processed independentlyof any other received signal that is associated with another differentset of measured parameters. For example, a first virtual channel maycorrespond to a phase difference between about 30 and 90 degrees. Anysignal that is received and has a measured phase difference betweenabout 30 and 90 degrees is assigned to the first virtual channel andprocessed according to individual adjustment parameters of the firstvirtual channel. A second virtual channel may correspond to a phasedifference between about 90 and 150 degrees. Any signal that is receivedand has a measured phase difference between about 90 and 150 degrees isassigned to the second virtual channel and processed according to theadjustment parameters of the second virtual channel. Multiple virtualchannels (e.g., up to N virtual channels, wherein N is typically greaterthan or equal to 1) may exist within a single communication channel buteach may be processed differently according to the associated measuredparameter of the received signal. Thus, the signal separator 212 doesnot typically physically separate received signals into differentcommunication channels. Instead, the signal separator 212 creates anassociation between a received signal and its set of measuredparameters. Of course, embodiments can be envisioned where the signalseparator 212 separates each received signal according to thecorresponding set of measured parameters and subsequently assigns thereceived signal to an actual communication channel that is dedicated toa single participant. This way any signal received at the microphonearray 204 would be separated into a dependent communication channelafter the origin of the signal has been identified by its measuredparameters.

The processor 216, using routines stored in the memory 220, operates, atleast in part, to alter signals received from the microphone array 204.Specifically, the processor 216 is operable to independently processeach virtual channel. For instance, assuming there are four participantssharing the enhanced communication device 216, and each participant hasbeen assigned to a different virtual channel, then the enhancedcommunication device 216 is operable to adjust properties of a signal inthe first virtual channel without adjusting any properties of a signalin the second virtual channel. Likewise, the third and fourth virtualchannels may be processed independently as well.

The processor 216 identifies the virtual channel for a received signalby referencing the set of measured parameters that have been linked tothe received signal. Then based on the identified virtual channel, theprocessor 216 can alter the signal if such an action is desired.Examples of suitable alterations that can be performed on a receivedsignal include, but are not limited to, muting the signal, increasingthe volume of the signal, decreasing the volume of the signal, and soon. The processor 216 is not necessarily required to alter a particularsignal and therefore, the selective alteration of a received signal isachieved.

The processor 216 may be suitable type of microprocessor, a ReducedInstruction Set Computer (RISC), a Complex Instruction Set Computer(CISC), an Application Specific Integrated Circuit (ASIC), or other typeof processing equipment. Furthermore, functions performed by theparticipant locator 208 and signal separator 212 may be performedcompletely or in part by the processor 216.

The memory 220 includes logical instructions for the participant locator208, signal separator 212, and/or processor 216 to perform as well asmemory storage buffers. The memory 220 may be any type of memoryincluding Random Access Memory (RAM), Read Only Memory (ROM), DynamicRAM (DRAM), Flash Memory, Electronically Programmable ROM (EPROM), andthe like.

As will be appreciated, one or more of the components of the enhancedcommunication device 116, such as the participant locator 208, thesignal separator 212, and the processor 216, may be included in theconference bridge 112 or a switch/server rather than in thecommunication device 116. The processing steps may be completelyperformed at an enhanced communication device 116 separate from theconnection point (e.g., the server/switch or the conference bridge 112).Alternatively, certain processing steps may be performed separately butmanaged locally or all processing steps may be performed and managedlocally at a server/switch or conference bridge 112. For example, theenhanced communication device 116 may separate voice signals intovirtual lines, and assign each virtual line to an actual line before itis forwarded on to the conference bridge 112. The conference bridge 112may adjust parameters of signals received on each line independentlythen forward the adjusted signals on to the receiving endpoint. If thevirtual channels are distributed at the enhanced communication device116, then the conference bridge 112 can rely on typical processingfunctions in the processor 120. Alternatively, a composite receivedsignal can be transmitted from the enhanced communication device 116 tothe conference bridge 112 where different signals from differentparticipants are split into virtual lines and then processed prior totransmission to another communication device 116.

The user interface 224 may include a touchtone keypad or some other typeof user input for dialing numbers to call. The user interface 224 mayalso comprise a visual display as an output device that shows a one ormore of the sharing participants where it believes the participants arelocated relative to the enhanced communication device 116. The displayportion of the user interface may be in the form of a Liquid CrystalDisplay (LCD) screen, a set of Light Emitting Diodes (LEDs), a singleLED, a clock face with arrows, a Cathode Ray Tube (CRT) display, orother type of mechanism able to articulate information to participantsusing the enhanced communication device 116.

The transceiver 228 is operable to receive signals from thecommunication network 104 for transmission to the participants using theenhanced communication device 116. The transceiver 228 is also operableto transmit signals, either over a single communication channel, virtualchannels, or via separate dedicated channels. Examples of suitabletransceivers include an Ethernet port or other type of network adapter,a modem, or a plain old telephone line.

With reference to FIG. 3A an enhanced communication device 116 equippedfor distinguishing the location of participants will be described inaccordance with at least some embodiments of the present invention. Theenhanced communication device 116 depicted in FIG. 3A comprises amicrophone array 204 which subsequently encompasses two microphones. Afirst participant 304 a is located in a first position relative to themicrophone array 204. A second participant 304 b is located in a secondposition relative to the microphone array 204. These participants lie indifferent spatial positions along a single axis (i.e., the x-axis 308).Although the participants are depicted as sitting diametrically opposedto one another in relation to the microphone array 204, the microphonearray 204 would function properly if each of the participants weresitting closer to one another, for instance on the top side of thetable. As can be appreciated by one of skill in the art, additionalparticipants may share the enhanced communication device 116 and may bepositioned at any point on or around the table. The use of twomicrophones in the microphone array 204 allows the participant locator208 to at least identify a location of participants along the x-axis308.

In operation each microphone in the microphone array 204 receives asingle voice signal from the first 304 a and/or second 304 bparticipant. When the first participant 304 a speaks, the microphoneclosest to the first participant 304 a (i.e., the left-most microphone)receives the voice signal first. The microphone that is further awayfrom the first participant 304 a (i.e., the right-most microphone)receives the voice signal at some time after the first microphonereceived the voice signal, due to the additional distance the signalmust travel. The waveform of each received signal is essentially thesame, assuming they are not spaced extremely far apart. However, thesignal from the first microphone is offset in phase from the signal fromthe second microphone. The phase difference generally corresponds to aposition somewhere along the x-axis 308. Assuming the center of themicrophone array 204 (i.e., the midpoint between the two microphones) isthe zero mark of the x-axis, the participant locator 208 correlates asignal received at the left-most microphone before it is received at theright-most microphone to have originated somewhere left of themicrophone array 204. The greatest possible phase difference means thatthe speaking participant is located directly across the left microphonefrom the right microphone. In other words, the speaking participant islocated on the x-axis formed by the two microphones. A lesser phasedifference means that the speaking participant is located somewherebetween the center of the microphone array 204 and the axis formed bythe two microphones. In the event that no phase difference is measuredbetween the signal received at the right and left microphones, then theparticipant locator 208 can determine that the speaking participant islocated at the center point of the x-axis 308. The participant locator208 is operable to determine that the speaking participant is locatedthe same distance from the left microphone as he/she is from the rightmicrophone. This location is only possible at the center of the x-axis308.

One drawback to using a microphone array 204 equipped with only twomicrophones is that locations of speakers can only be determined alongone axis. In other words, if two participants were seated directlyacross the table from each other and both were on the center point ofthe x-axis 308, then the participant locator 208 would likely confusethese participants because the phase difference for each participantwould be substantially zero.

To remedy this problem a microphone array 204 equipped with threemicrophones may be employed. With reference to FIG. 3B an enhancedcommunication device 116 equipped with a microphone array 204 havingthree microphones will be described in accordance with at least someembodiments of the present invention. A microphone array 204 equippedwith three microphones is operable to identify the location ofparticipants in two dimensions. Specifically, the location of aparticipant may be determined in both the x-axis 308 and y-axis 312. Thex-axis 308 and y-axis 312 both lay a plane defined by the threemicrophones of the microphone array 204. Typically, the plane formed bythe three microphones of the microphone array 204 is typically parallelto a floor, table, or some other common surface. However, the threemicrophones may be tilted relative to a common surface if doing so isfound desirable. Any configuration of the microphones in the microphonearray 204 may be suitable depending upon the application envisioned.

With three microphones participants may sit directly across from eachother along one axis and the participant locator 208 can still discernbetween the participants based on their location along the other axis.As shown in FIG. 3B, the six participants 304 a-f are sitting around atable or the like that is supporting the enhanced communication device116. In the event that the first participant 304 a is speaking, theleft-most microphone will receive the voice signal before the center andright-most microphones. Also, the center microphone will receive thevoice signal before the right-most microphone. The waveform received ateach microphone will be substantially the same but each waveform will beoffset by the other waveforms by some amount of phase shift. Based onthe difference between phases of the signal received at the first,second, and third microphones, the participant locator 208 will be ableto determine the location of the first participant 304 a along thex-axis 308 and the y-axis 312. More interestingly, however, when threemicrophones are used the second participant 304 b may be distinguishedfrom the sixth participant 304 f. When the second participant 304 bspeaks, a phase difference will exist between each of the signalsreceived at each of the microphones. Specifically, a first differencewill exist between the left-most and the right-most microphone, a seconddifference will exist between the left-most and the center microphone,and a third difference will exist between the right-most and the centermicrophone. When the sixth participant 304 f speaks, the phasedifference between the right-most and the left-most microphone will mostlikely be the same as the phase difference for the second participant304 b. However, the phase difference between the center microphone andthe other microphones will differ from the phase differences measuredfor the second participant 304 b. By using some or all of the phasedifferences the participant locator 208 will be operable to determinethe respective location of each participant relative to the microphonearray 204 and will therefore be able to assign each participant to adedicated virtual channel.

With reference to FIG. 3C an enhanced communication device 116 equippedwith a microphone array 204 having more than three microphones will bedescribed in accordance with at least some embodiments of the presentinvention. Ultimately, the use of three microphones limits thedetermination of location to two dimensions in the plane of the threemicrophones. To determine the location of participants in threedimensions more than three microphones should be utilized and at leastone of the three microphones should be out of a plane formed by theother three microphones. Using more than three microphones allows theparticipant locator 208 to determine the location of a participant inthe x-axis 308, y-axis 312, and the z-axis 316. The depicted axes arearbitrary and any set of coordinates may be utilized in order to definethe location of a particular participant. Specifically, polarcoordinates like distance away from the microphone array 204 along withangle of the participant relative to the microphone array 204 may beused to define where a participant is located rather than the Cartesiancoordinate system described herein.

When more than three microphones are used it may be possible todistinguish between participants that are standing up and otherparticipants that are sitting down. Additionally, when more microphonesare used it becomes possible to accurately identify the location of moreparticipants because more phase differences can be measured andcorrelated to a particular participant. A further discussion ofmicrophone arrays and their uses can be found in Audio-Video ArraySource Separation for Perceptual User Interfaces by Wilson et al., thecontents of which are herein incorporated by this reference.

Referring now to FIG. 4 an exemplary user interface 224 will bedescribed in accordance with at least some embodiments of the presentinvention. The user interface 224 may be operable to display where itbelieves the possible locations of a participant are related to themicrophone array 204. For example, in the depicted embodiment, fourparticipants are sharing an enhanced communication device 116. Theparticipant locator 208 has determined the location of the participantsto a certain degree of certainty and assigned a different quadrant ofthe room to each participant.

As used herein a “room” is any space that is around the enhancedcommunication device. The term room is not meant to limit embodiments ofthe present invention to spaces that are enclosed with walls or thelike.

The quadrants assigned to each of the four participants 304 a-d are notnecessarily equal portions of the room. For example, the firstparticipant 304 a may be assigned to a first portion of the room that isbetween about 0 and 15 degrees as measured by the horizontal axis. Theangle of about 0 to 15 degrees may correspond to a first amount ofmeasured phase shift at the microphone array 204. The second participant304 b may be assigned to a second portion of the room that is betweenabout 15 and 180 degrees. This particular participant may be assigned alarger portion of the space around the enhanced communication device116. As can be appreciated by one of skill in the art, a portion andcorresponding phase shift range that a participant is associated withshould not overlap with another portion and corresponding phase shiftrange for another participant. In other words, each of the assignedphase shift ranges should be mutually exclusive for each participant. Onthe other hand, the phase shift ranges do not necessarily need to becollectively exhaustive of the possible ranges around the microphonearray 204. However, in a preferred embodiment the participant locator208 will assign a first participant to the entire room. Then whenanother participant is identified, the participant locator will dividethe room evenly among the first and second participant. As additionalparticipants continue to share the enhanced communication device 116,the participant locator will continue to sub-divide the space around themicrophone array 208 accordingly.

The location of various participants and/or their designated portionsmay be displayed by an arrow pointing to the participant (i.e., theperceived origin of a voice signal), a pie chart depicting which portionor range of angles relative to the microphone array 204 each participantis associated with, an LED or LCD depicting the name of the identifiedparticipant based on his/her location, or some other type of display.

The user interface 224 may also comprise inputs that allow the sharingparticipants to mute either their own voice by touching the displayshowing their location. This way, in the event that three or moreparticipants are sharing an enhanced communication device 116, two ofthose participants may mute their voice (i.e., associatedportion/virtual channel) without muting all other participants. The twoparticipants that mute their virtual channels will be able to have aside conversation without muting all other participants that are sharingthe enhanced communication device 116. Alternatively, one participantcan mute several participants including him/herself. Moreover, a portionof the room may be muted that does not necessarily correspond to aparticipant. For example, a projector with a noisy fan or anair-conditioning vent can be selectively muted such that it is not heardby the listening participant(s). Thus, the enhanced communication device116 is dynamically scalable to provide more or less virtual channels asmore or less participants wish to share the communication device 116.

The user interface 224 is further operable allow a participant to muteother individual participants in the conference call. For example, if alistener and speaker are equipped with an enhanced communication device116, then the listening party may be displayed which participant iscurrently speaking and their associated virtual channel. The listeningparticipant may be able to selectively mute the virtual channelassociated with just one of the speaking participants sharing the otherenhanced communication device 116. This way, the listening party canchoose which participant he/she is listening to even though thatparticipant may be sharing the enhanced communication device 116 withother participants that the listener would like to hear.

Referring now to FIG. 5 a data structure 504 employed by at least someembodiments of the present invention will be described. The datastructure 504 comprises a participant data field 508, a phase differencedata field 512, and an adjustment parameter field 516. The datastructure 504 may be stored in the memory 220 of the enhancedcommunication device 116, in a memory of the conference bridge 112,and/or in an external database. When a new participant is identified,for example, by the participant locator 208, voice recognition software,or by the participant pressing a button on the user interface 224indicating that he/she would like to share the enhanced communicationdevice 116, the participant is added to the participant data field 508.The data relating to a participant may simply be an arbitraryidentification number assigned to each participant as they are added tothe conference, such that the first participant that is identified isgiven the number one, the second participant is assigned the number two,and so on. Alternatively, the data may be more detailed identificationinformation if such information is available for a participant. Moredetailed identification information may be entered by the participantinto the enhanced communication device 116 prior to beginning aconference call or may be referenced from an external database used tostore such information. If more detailed information is available for aparticipant, then that information can be forwarded to otherparticipants of the conference call when a participant is speaking. Thismay allow the other listening participant to know whether or not theywould like to mute the speaking participant.

The participant locator 208 dynamically populates the phase differencedata field 512 as additional participants share the enhancedcommunication device 116 or as participants quit sharing the enhancedcommunication device 116. As a participant speaks the phase differencemeasured by the microphone array 204 is analyzed and the participantlocator 208 determines the approximate location of the speakingparticipant relative to the microphone array 204. Thereafter, theparticipant locator 208 determines how many participants are alreadysharing the enhanced communication device 116. If no participants arecurrently sharing the enhanced communication device 116, then the firstparticipant may be assigned all possible phase differences in the phasedifference field 512 even though the participant locator 208 knowsapproximately the phase difference(s) for the first participant and thuswhere he/she is located. Alternatively, the exact phase differencemeasured at the microphone array 204 may be entered into the phasedifference array 512.

When a second participant begins to share the enhanced communicationdevice 116, the participant locator 208 is operable to analyze the phasedifference of the voice signal received at the microphone array 204 todetermine the approximate location of the second participant.Alternatively, the second participant may manipulate the user interface224 such that the enhanced communication device 116 knows theapproximate location of the second participant. Now that there are twoparticipants sharing the enhanced communication device 116, theparticipant locator 208 may assign a first portion of the room to thefirst participant and a second portion of the room to the secondparticipant. The size of each portion does not necessarily need to beequal in size. However, such an implementation would be an easy way todivide the room. The phase difference corresponding to each portion ofthe room is entered into the phase difference field 512 by theparticipant locator 208. The signal separator 212 uses the associationof the phase difference to a participant when a received signal isassigned a virtual channel. If a received signal has a phase differencewithin the phase difference range for the first participant, then thesignal separator 212 will assign the received signal to a first virtualchannel. However, if the received signal has a phase difference withinthe phase difference range for the second participant, then the signalseparator 212 will assign the received signal to a second virtualchannel. As additional participants are added, the participant locator208 will continue to re-divide the room and corresponding phasedifference ranges among the sharing participants and the signalseparator 212 will be able to assign each new participant to a newvirtual channel accordingly.

Each of the virtual channels may have a different adjustment parameterassociated with them. The information related to the adjustmentparameters for a virtual channel is maintained in the adjustmentparameters field 516. The sharing participants of the enhancedcommunication device 116 may define the adjustment parameters. Forexample, when a sharing participant wishes to mute or adjust his/her ownvoice. Alternatively, other participants across the communicationnetwork 104 may define adjustment parameters. For instance, voicesignals may be transmitted across the communication network 104 withtheir associated phase difference, such that the receiving participant'scommunication device can substantially identify the speaking participantbased on his/her phase difference. The receiving participant may chooseto mute or alter a subset of the participants whom are sharing theenhanced communication device 116. As noted above, as long as anassociation between a measured phase (or amplitude) difference at themicrophone array 204 and a participant is maintained, a signal may beassigned to a virtual channel and adjusted independently of othersignals received at the same microphone array 204 having differentmeasured differences. The originating enhanced communication device 116associated with the speaking participant, the conference bridge 112, orthe targeted enhanced communication device 116 associated with thelistening participant may perform the adjustments that are defined inthe adjustment parameters 516. Furthermore, any one of the above noteddevices may define the adjustment parameters in the adjustment parameterfield 516 for another device to perform. For example, the listeningparticipant may define that he/she would like to have the one of thesharing participant's voice turned up. The originating enhancedcommunication device may increase the volume for that particularparticipant's virtual channel prior to transmitting the voice signal tothe listening participant.

Referring now to FIG. 6, a method of initializing a conference call willbe described in accordance with at least some embodiments of the presentinvention. Initially, the conference call participants are determined(step 604). As noted above, each participant may be required to engage abutton or the like on the user interface 224 indicating that he/she willbe sharing the enhanced communication device 116. The enhancedcommunication device 116 can keep a tally of how many participants aresharing the device, thus allowing the participant locator to divide theroom relatively accurately. Alternatively, a participant may beidentified before conference call even begins. Further in thealternative, the participant locator 208 may simply monitor receivedvoice signals and attempt to discern between different participantsbased on the origin of their voice.

After a participant has been determined, the participant locator 208identifies a location for that participant (step 608). Typically, thelocation as identified by the participant locator 208 is a locationrelative to the microphone array 204. The location of the participant isthen expanded by the participant locator 208, usually depending upon thenumber of sharing participants, to include a location range for eachparticipant (step 612). The ranges assigned to each participant do notneed to be the same size. The signal separator 212 then assigns eachlocation range, i.e., phase difference range, to a particular virtualchannel (step 616). This assignment is maintained through the durationof the conference call, unless the number of sharing participantschanges, such that each participant can be uniquely identified byhis/her location relative to the microphone array 204. As a result, thevoice signal of each participant can be independently treated andadjusted.

In accordance with at least some embodiments of the present invention,the participant locator 208 is operable to identify when a participanthas moved during a conference call. For example, assume that twoparticipants are seated directly opposite one another in relation to themicrophone array 204. With this particular orientation, the participantlocator 208 can assign one half of the room to a first participant andthe other half of the room to a second participant. Now assume that thesecond participant moves around the microphone array 204 closer to thefirst participant. When the second participant begins to speak, theparticipant locator 208 is operable to identify a new location for theparticipant and assign a portion of the room to the participant. Theparticipant locator 208 may identify the participant based on voicequalities of the participant by analyzing spectral properties (i.e.,frequency, pitch, etc.) of the participant's voice and can re-divide theroom into two portions that correspond to the new locations of the firstand second participant. Alternatively, the participant locator 208 maynot attempt to identify the participant based on his/her speechqualities, but rather may simply assume the second participant isactually a new third participant. The participant locator 208, based onthis assumption, may divide the room into three portions. The signalseparator 212 may correspondingly assign a third virtual line to theassumed third participant (who is actually the second participant). Asthe conference continues, the participant locator 208 may monitor eachportion of the room for voice activity. After a predetermined amount oftime has passed, and the participant locator 208 has not detected anyvoice activity from the second participant's previous location, theparticipant locator 208 may determine that the second participant is nolonger using his/her previous location and may re-divide the room intotwo portions corresponding to the new locations of the first and secondparticipants. It may prove beneficial to continuously update the roomdivision such that it accurately represents the number of activeparticipants sharing the enhanced communication device 116.

Referring now to FIG. 7 a method of processing a participant's voicesignal will be described in accordance with at least some embodiments ofthe present invention. The method begins when a signal is received atthe microphone array (step 204). This means that the received signal hasbeen received at least two of the microphones in the microphone array204. Thereafter, the location of the signal is determined (step 708). Asnoted above, the location, or location relative to the microphone array204, may be determined by measuring the phase difference of the receivedsignal at the microphone array 204. Alternatively or in combination, anamplitude difference between received signals may be measured todetermine the location of a speaking participant. Based on the location,the signal separator 212 assigns the voice signal to a virtual channeland the adjustment parameters are determined for the given location(step 712). The types of adjustments that may be performed on a givensignal include muting the signal, increasing the volume of the signal,decreasing the volume of the signal, altering the playback speed of thesignal, and the like. After the adjustment parameters have beendetermined, the processor 216 adjusts the received signal based on itscorresponding adjustment parameters. Another received signal from adifferent location may have a different set of corresponding adjustmentparameters and therefore the adjustment parameters, if any, of each ofthe virtual channels may be substantially unique to that channel. Moreinterestingly, however, each channel can be processed substantiallyindependently of any other virtual channel because each channel has anassociated location range. After the received signal has been properlyadjusted, if such an action was necessary, then the adjusted signal istransmitted across the communication network 104 to the receivingcommunication device 108 and/or the communication bridge 112 (step 720).As noted above, the adjustment of a received signal does not necessarilyneed to be performed at the transmitting enhanced communication device108. Rather, any suitable processor located within the communicationsystem 100 may perform the adjustment.

In accordance with at least some embodiments of the present invention,the enhanced communication device 116 is operable to normalize thereceived signals of each of the sharing participants. Typically, whenmultiple participants share a communication device, some participantssit further away from the device than other participants. Therefore,even if each participant is speaking at the same decibel level, thereceiving party perceives some participants to be speaking louder thanother participants. However, because each virtual line associated witheach participant can be processed independently, participants that aresharing the enhanced communication device 116 may appear to all bespeaking at the same volume when the listener receives the signal fromthe enhanced communication device 116.

Furthermore, additional location technologies may be employed to augmentaudio location. For example, video monitoring may be utilized in orderto assist the microphone array 204 in locating and tracking a particularparticipant during a conference. Suitable video monitoring techniquesincluding mono and stereo video tracking may be used when the locationof a source of sound is being determined. Additionally, the participantlocator 208 may employ radio location (i.e., RFID tracking) to furtherincrease the accuracy with which participants are tracked and located.For example, participants may be given RFID tags that can be located andtracked by an RFID scanner.

The present invention, in various embodiments, includes components,methods, processes, systems and/or apparatus substantially as depictedand described herein, including various embodiments, subcombinations,and subsets thereof. Those of skill in the art will understand how tomake and use the present invention after understanding the presentdisclosure. The present invention, in various embodiments, includesproviding devices and processes in the absence of items not depictedand/or described herein or in various embodiments hereof, including inthe absence of such items as may have been used in previous devices orprocesses, e.g., for improving performance, achieving ease and\orreducing cost of implementation.

The foregoing discussion of the invention has been presented forpurposes of illustration and description. The foregoing is not intendedto limit the invention to the form or forms disclosed herein. In theforegoing Detailed Description for example, various features of theinvention are grouped together in one or more embodiments for thepurpose of streamlining the disclosure. This method of disclosure is notto be interpreted as reflecting an intention that the claimed inventionrequires more features than are expressly recited in each claim. Rather,as the following claims reflect, inventive aspects lie in less than allfeatures of a single foregoing disclosed embodiment. Thus, the followingclaims are hereby incorporated into this Detailed Description, with eachclaim standing on its own as a separate preferred embodiment of theinvention.

Moreover though the description of the invention has includeddescription of one or more embodiments and certain variations andmodifications, other variations and modifications are within the scopeof the invention, e.g., as may be within the skill and knowledge ofthose in the art, after understanding the present disclosure. It isintended to obtain rights which include alternative embodiments to theextent permitted, including alternate, interchangeable and/or equivalentstructures, functions, ranges or steps to those claimed, whether or notsuch alternate, interchangeable and/or equivalent structures, functions,ranges or steps are disclosed herein, and without intending to publiclydedicate any patentable subject matter.

1. A method of facilitating a conference call, comprising: receiving, bya processor, a sound signal; determining, by the processor, a relativespatial location of a source of the received sound signal; based on thedetermined location of the source of the received sound signalprocessing the received sound signal by performing at least one of thefollowing steps: selectively altering, by the processor, the receivedsound signal in a first manner in the event that the received soundsignal is received from a first determined location; selectivelyaltering, by the processor, the received sound signal in a second mannerin the event that the received sound signal is received from a seconddetermined location, wherein the first and second manners are different;creating, by the processor, a virtual channel for the received soundsignal; creating, by the processor, sound parameters for the virtualchannel; storing, by the processor, the selective alteration in thesound parameters; and transmitting, by the processor, the virtualchannel with the stored sound parameters.
 2. The method of claim 1,wherein the first and second sets of spatial locations are mutuallyexclusive.
 3. The method of claim 1, further comprising assigning thereceived sound signal to one of at least two virtual channels, wherein afirst virtual channel is associated with a first set of spatiallocations, and wherein a second virtual channel is associated with asecond set of spatial locations, wherein a received sound signalassigned to the first virtual channel is muted and a received soundsignal assigned to the second virtual channel is not altered.
 4. Themethod of claim 3, wherein a first participant is associated with thefirst virtual channel and wherein a second participant is associatedwith the second virtual channel.
 5. The method of claim 4, furthercomprising: dividing a room into at least two portions; assigning thefirst participant to a first of the at least two portions; assigning thesecond participant to a second of the at least two portions; and whereinthe first of the at least two portions is associated with the firstvirtual channel and the second of the at least two portions isassociated with the second virtual channel.
 6. The method of claim 5,further comprising: monitoring the first and second portions for voiceactivity; determining that voice activity has not occurred in at leastone of the portions for a predetermined amount of time; and removing theat least one portion of the room that has not had any determined voiceactivity for the predetermined amount of time.
 7. The method of claim 1,further comprising: providing a microphone array comprising at least twomicrophones; receiving the sound signal at a first of the at least twomicrophones at a first time; receiving the sound signal at a second ofthe at least two microphones at a second time; determining a difference,if any, between the first and second time; and wherein the spatialorigin of the received sound signal is determined based at least in parton the difference between the first and second time.
 8. The method ofclaim 1, further comprising: associating the first determined locationwith a first phase delay range; measuring a phase delay of the receivedsound signal; determining whether the phase delay of the received soundsignal lies between the first phase delay range; and assigning thereceived sound signal to a first virtual channel in the event that thephase delay of the received sound signal lies within the first delayrange.
 9. The method of claim 1, wherein selectively altering comprisesat least one of, muting, increasing the volume, and decreasing thevolume of the received sound signal.
 10. The method of claim 1, furthercomprising displaying first and second determined locations.
 11. Acomputer readable medium comprising executable instructions operable toperform the method of claim
 1. 12. A device for use in a conferencecall, wherein at least a first and second participant share a singlecommunication device, comprising: an input operable to receive a firstsound signal from the first participant and a second sound signal fromthe second participant; a participant locator operable to determine aspatial location of the first sharing participant; a signal separatoroperable to, based on the determined spatial location of the firstsharing participant, distinguish the sound signals received from thefirst sharing participant from the sound signals received from thesecond sharing participant; a processor operable to: process soundsignals received from the first sharing participant independently ofsound signals received from the second sharing participant; create afirst virtual channel for the first sound signal; store the first soundsignal and at least one parameter describing the first sound signal inthe first virtual channel; create a second virtual channel for thesecond sound signal; and store the second sound signal and at least oneparameter describing the second sound signal in the second virtualchannel.
 13. The device of claim 12, wherein the signal separator isfurther operable to assign the received sound signals to the virtualchannels based on the determined spatial location of the sharingparticipants, wherein a first virtual channel is associated with a firstspatial location, wherein a second virtual channel is associated with asecond spatial location, and wherein the first and second sets ofspatial locations are mutually exclusive.
 14. The device of claim 12,wherein a received sound signal from the first participant is muted anda received sound signal from the second participant has a volumeincreased.
 15. The device of claim 13, wherein the first participant isassociated with the first virtual channel and wherein the secondparticipant is associated with the second virtual channel the at leastone parameter allows the sound signals to be adjusted.
 16. The device ofclaim 12, wherein the participant locator is further operable to dividea room into at least two portions, assign the first sharing participantto a first of the at least two portions, assign the second sharingparticipant to a second of the at least two portions.
 17. The device ofclaim 12, wherein the input comprises a microphone array comprising atleast two microphones, wherein a first of the at least two microphonesis operable to receive the sound signal at a first time, wherein asecond of the at least two microphones is operable to receive the soundsignal at a second time.
 18. The device of claim 17, wherein theparticipant locator is further operable to determine a difference, ifany, between the first and second time and substantially determine thespatial location of the origin of the received sound signal based atleast in part on the difference between the first and second time. 19.The device of claim 12, wherein the participant locator is furtheroperable to associate the first participant with a first phase delayrange, measure a phase delay of the received sound signal, determinewhether the phase delay of the received sound signal lies between thefirst phase delay range, and assign the received sound signal to thefirst virtual channel in the event that the phase delay of the receivedsound signal lies within the first delay range.
 20. The device of claim13, wherein the processor is operable to perform at least one of mute,increase the volume, and decrease the volume of the received soundsignal in one of the at least two virtual channels without requiring thesame change in another of the at least two virtual channels.
 21. Thedevice of claim 13, further comprising a user interface operable todisplay the spatial locations associated with the first and secondvirtual channel to the first and second sharing participant.
 22. Amethod of facilitating a conference call, comprising: receiving, by aprocessor, a sound signal; determining, by the processor, a relativespatial location of a source of the received sound signal; based on thedetermined location of the source of the received sound signal,assigning, by the processor, the received sound signal to one of atleast two virtual channels, wherein a first virtual channel isassociated with a first set of spatial locations, wherein a secondvirtual channel is associated with a second set of spatial locationsstoring, by the processor, a first set of parameters for the first setof spatial locations with the first virtual channel; storing, by theprocessor, a second set of parameters for the second set of spatiallocations with the second virtual channel; and processing, by theprocessor, the received sound signal by performing at least one of thefollowing steps: selectively muting the first virtual channel,increasing the volume of the first virtual channel by a first amount,and/or decreasing the volume of the first virtual channel by a firstamount in the event that the received sound signal is assigned to thefirst virtual channel; and selectively muting the second virtualchannel, increasing the volume of the second virtual channel, and/ordecreasing the volume of the second virtual channel in the event thatthe received sound signal is assigned to the second virtual channel. 23.The method of claim 22, wherein the first and second sets of spatiallocations are mutually exclusive.
 24. The method of claim 22, wherein areceived sound signal assigned to the first virtual channel is muted anda received sound signal assigned to the second virtual channel is notaltered.
 25. The method of claim 22, wherein a first participant isassociated with the first virtual channel and wherein a secondparticipant is associated with the second virtual channel.
 26. Themethod of claim 25, further comprising: dividing a room into at leasttwo portions; assigning the first participant to a first of the at leasttwo portions; assigning the second participant to a second of the atleast two portions; and wherein the first of the at least two portionsis associated with the first virtual channel and the second of the atleast two portions is associated with the second virtual channel. 27.The method of claim 22, further comprising: providing a microphone arraycomprising at least two microphones; receiving the sound signal at afirst of the at least two microphones at a first time; receiving thesound signal at a second of the at least two microphones at a secondtime; determining a difference, if any, between the first and secondtime; and wherein the spatial origin of the received sound signal isdetermined based at least in part on the difference between the firstand second time.
 28. The method of claim 22, further comprising:associating the first virtual channel with a first phase delay range;measuring a phase delay of the received sound signal; determiningwhether the phase delay of the received sound signal lies between thefirst phase delay range; and assigning the received sound signal to thefirst virtual channel in the event that the phase delay of the receivedsound signal lies within the first delay range.
 29. A computer readablemedium comprising executable instructions operable to perform the methodof claim 22.